BLOOD TYPING - Humble Independent School District



4564583-63611800Name__________________________________________date_____FS-_____BLOOD TYPINGDirections: 1. Place 2-3 drops of blood into each of the 3 wells (labeled A B Rh) 2. Place 3-6 drops of anti-A into A, anti-B into B and Rh into Rh 3. Using a different toothpick, stir gently 4. Record blood type for suspect 1,2,3, weapon, CS and victim452079493777weaponweapon45207942021001Weapon_____00Weapon_____Questions: Why is simulated (man-made) blood used instead of real human blood in this activity?(list 2 reasons)Human blood is costly , not easily purchased, rapid decomp, may contain pathogens Explain why it is necessary to type the victim’s blood when trying to determine if any of the blood found at the crime scene belongs to a particular suspect.Vic’s blood must be EXCLUDED as evidence. If the vic and crime scene blood matches, then OTHER evidence would be needed (hair, fingerprints)List all of the blood-type proteins examined in this activity._A B Rh(type O blood had NO proteins and does not react with chemicals)Is it possible to exclude any of the suspects based on blood types? Explain your answer.Suspects 2 and 3 are excluded because their blood types do NOT match the CSBased on your results, does the crime-scene blood match the blood type of any of the 3 suspects? Explain your answer.Suspect #1 matches by having type A+If blood from one of the suspects matches the crime-scene blood, does that prove that the suspect is guilty? Explain your answer.Blood TYPE is considered CLASS evidence, and all people share one of the four types. Having type A+ blood does NOT put you at the scene. Poor laboratory techniques may lead to erroneous results that could impact the outcome of a trial. List 3 examples of poor laboratory techniques involved in a blood-typing analysis that might produce erroneous results. Misread the resultsMixed up the reactantsStirred the blood mixtures with the same toothpickDidn’t use enough blood/reactantExplain why identifying the blood type found in both the suspect and at a crime scene as AB– provides a higher degree of probability of a match than if the blood type found in the suspect and at the crime scene is O+.Type AB- blood is extremely rare, less than 1% of the population shares this type. Having a rare blood type makes a suspect a part of a very small population…narrowing the search ................
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